Hyperhomocysteinemia in rheumatoid arthritis: influence of methotrexate treatment and folic acid supplementation

OBJECTIVE: To examine the effect of methotrexate (MTX) and folic acid supplementation on the homocysteine level in patients with rheumatoid arthritis (RA). METHODS: A cross sectional study was performed in 81 patients with RA, comprising a standardized clinical interview, an examination, and a blood specimen test. RESULTS: P-homocysteine tended to be lower in 41 patients receiving MTX, compared with 40 patients not receiving MTX. Of the MTX treated patients, 76% received folic acid supplementation. Multivariate analysis revealed a statistically significant association between P-homocysteine and P-creatinine (p < 0.001), and disease activity/progression measured by the Health Assessment Questionnaire score (p < 0.001). There was a tendency to negative association between P-homocys-teine and folic acid supplementation. CONCLUSION: P-homocysteine in patients with RA receiving MTX and folic acid supplementation did not differ significantly from P-homocysteine in RA patients receiving other types of treatment.     

Genotoxicity assessment using micronuclei assay in rheumatoid arthritis patients

OBJECTIVES: This study investigated whether: (i) rheumatoid arthritis (RA) patients have more micronuclei (MN) than healthy controls; (ii) methotrexate (MTX) treated RA patients have more MN than those not using MTX, and (iii) folic acid supplementation decreases the number of MN in MTX treated patients. METHODS: MN assays were performed in oral mucosa sweeps of 50 consecutive MTX treated RA patients, 30 consecutive RA patients not receiving MTX and 39 healthy controls. MTX treated RA patients were then randomly placed in a cross-over design to receive folic acid supplementation, and MN assays were repeated after 6 weeks. RESULTS: The MTX-RA patients had a mean age of 46 +/- 10 yrs and a mean disease duration of 12 +/- 9 yrs; 80% were women. The MTX dose range was 8.7 +/- 1.5 mg/week and the mean duration of use was 16 +/- 18 months. In the non-MTX RA group, the mean age was 48 +/- 14 yrs, the mean disease duration was 13 +/- 9 yrs, and 87% were women. At baseline, the number of MN were significantly higher in RA patients as compared with controls (3.31 +/- 2.3 vs 0.8 +/- 0.8, p <0.001). No difference in MN numbers was observed between users and non-users of MTX. Folic acid supplementation did not decrease the MN number in the MTX treated RA patients. CONCLUSIONS: Genotoxicity, as assessed by the MN assay, is increased in RA patients. These results suggest that genotoxicity is associated with RA itself and not with MTX use. Folic acid supplementation had no effect on the number of MN.     

Economic evaluation of folate supplementation during methotrexate treatment in rheumatoid arthritis

OBJECTIVE: To determine cost-effectiveness of folic or folinic acid supplementation in patients with rheumatoid arthritis (RA) who started methotrexate (MTX) treatment. METHODS: An economic evaluation, performed alongside a randomized, double blind, placebo controlled trial with followup of 48 weeks. Patients started MTX with placebo (n = 137), folic acid (n = 133), or folinic acid (n = 141). Outcome measures were drug survival and quality-adjusted life-years (QALY), measured with the EuroQol questionnaire. Both medical and nonmedical costs were analyzed. RESULTS: Drug survival after 48 weeks was 60% for placebo, 81% for folic acid, and 87% for folinic acid. QALY during a 48 week period were 0.55 (95% CI 0.52-0.58) in the placebo group, 0.55 (95% CI 0.52-0.58) in the folic acid group, and 0.58 (95% CI 0.56-0.60) in the folinic acid group. Mean medical costs were 1398 US dollars (placebo), 1409 US dollars (folic acid), and 1776 US dollars (folinic acid). Mean total costs were 3339 US dollars, 3632 US dollars, and 3296 US dollars, respectively. CONCLUSION: In terms of resource deployment, no statistically significant difference was found between the 3 strategies. The preferred strategy consists of folic acid supplementation because of improved drug survival.     

The effect of folic acid and folinic acid supplements on purine metabolism in methotrexate-treated rheumatoid arthritis

OBJECTIVE: To determine if folinic acid supplementation during methotrexate (MTX) therapy for rheumatoid arthritis (RA) reduces both urinary 5-aminoimidazole-4-carboxamide (AICA) and urinary adenosine excretion more than does folic acid supplementation. AICA and adenosine are markers for MTX interference with purine metabolism. METHODS: Forty patients with RA who received MTX for 6 weeks were randomized to receive either daily folic acid or folinic acid supplements during an additional week of MTX therapy. Colorimetric and radioimmunocompetition assays were used to measure 24-hour urinary AICA and adenosine excretion levels, respectively. RESULTS: At the end of 6 weeks, 24-hour urinary levels of AICA, but not adenosine, were elevated as compared with baseline levels (i.e., prior to MTX therapy). Folinic acid, but not folic acid, supplementation normalized urinary AICA levels during MTX therapy. Relatively high urinary levels of AICA were correlated with reduced disease activity. No similar correlations were seen with urinary adenosine levels. CONCLUSION: The blockade of purine nucleotide biosynthesis by MTX at the AICA ribonucleotide transformylase-catalyzed step may be related to the efficacy of MTX, and this blockade is effectively relieved by folinic acid, but not by folic acid, supplementation.     

Intermittent rises in plasma homocysteine in patients with rheumatoid arthritis treated with higher dose methotrexate

OBJECTIVES: To investigate the effect of higher weekly maintenance dose methotrexate (MTX) (> or =25 mg/week) on plasma homocysteine concentrations in adults with RA. METHODS: Patients with RA were treated with high doses of MTX with adjuvant folic acid. Plasma homocysteine was determined at baseline and 1, 2, 4, 8, 12, and 48 hours after subcutaneous MTX administration. Maximum homocysteine concentrations after MTX administration were compared with baseline concentrations. RESULTS: Fifteen patients with RA (11 women) were included, with a median age of 61 years (range 31-72) and median disease duration 7 years (range 2-32). Median MTX dose was 30 mg (range 25-40). All patients received folic acid supplementation (5-30 mg/week). Median plasma homocysteine concentration at baseline was 10.1 mumol/l (range 6.6-12.7; normal 6-15). Homocysteine concentrations increased after MTX administration by a median of 2.5 mumol/l (range 0.7-5.1). Median maximum plasma homocysteine was significantly higher than at baseline. Peak homocysteine was reached after 12 hours. No relation between serum folate concentrations and plasma homocysteine concentrations was found. CONCLUSIONS: In patients with RA higher MTX doses with adjuvant folic acid do not increase baseline concentrations of homocysteine. An intermittent significant rise in plasma homocysteine occurs in the 48 hours after MTX administration.     

Folate, homocysteine, and cobalamin status in patients with rheumatoid arthritis treated with methotrexate, and the effect of low dose folic acid supplement

OBJECTIVE: To investigate the effect of methotrexate (MTX) treatment of rheumatoid arthritis (RA) on folate metabolism, and to determine the effect of low dose folic acid on toxicity, efficacy, and folate status. METHODS: A 52-week prospective study of 81 patients with RA treated with MTX and self-administered low dose folic acid; 38 patients were included prior to MTX therapy, 33 patients continued established MTX therapy, and 10 patients were excluded. Drug efficacy and side effects were monitored with biochemical and clinical indicators. RESULTS: MTX treatment resulted in decreased concentrations of red blood cell (RBC) folate and a rise in plasma homocysteine. Intracellular concentrations of MTX were inversely correlated to RBC folate levels after treatment for a longer period (mean 41 months). Supplement with low dose folic acid prevented or diminished the influence of MTX on folate status and had a protective effect on MTX induced liver toxicity without changing the efficacy of MTX. CONCLUSION: MTX interferes with folate and homocysteine metabolism, and the intracellular concentration of MTX may play a role. Our results indicate low dose folic acid supplementation has a beneficial effect on MTX toxicity.     

Reduction of the efficacy of methotrexate by the use of folic acid: post hoc analysis from two randomized controlled studies

OBJECTIVE: To examine the effect of folic acid on the efficacy of methotrexate (MTX) treatment in rheumatoid arthritis (RA) at 12 months in 2 phase III randomized controlled trials (RCTs) of leflunomide in which MTX was used as a comparator. METHODS: Analyses were restricted to patients randomized to receive MTX who had rheumatoid factor data. The US study recruited 482 patients with active RA; 179 received at least 1 dose of MTX, and all were mandated to receive 1 mg of oral folic acid once or twice daily. The multinational European study recruited 999 patients with active RA; 489 received at least 1 dose of MTX, and oral folic acid was not required, although 50 received folate after developing an adverse event. Because of similar entry criteria for both studies, the data for patients with available primary outcome data at week 52 were pooled (n = 668), and the patients were grouped by folic acid use (n = 225) and nonuse (n = 443). To account for the significant between-study differences in the MTX groups, baseline covariates were adjusted using propensity scores so that folic acid users could be matched with nonusers. This allowed for a comparison of differences in American College of Rheumatology (ACR) 20% improvement criteria at week 52. RESULTS: At study entry, non-folic acid users had a significantly lower mean body weight, shorter mean RA duration, and higher mean disease activity (measured by joint counts, patient's and physician's global assessments, and acute-phase reactant levels). The mean MTX dosage at week 52 was similar in the 2 RCTs. Using propensity score matching techniques, the proportion of patients achieving an ACR 20% response at week 52 averaged 17% higher in the non-folic acid group than in the folic acid group (range 15-21%). Similarly, the proportion of patients achieving ACR 50% and ACR 70% responses averaged 14% (range 12-16%) and 12% (range 9-14%) higher, respectively, in the non-folic acid group. Adverse events were reported in 93% of US study patients and 94% of the multinational study patients. Elevated liver transaminase levels (above the upper limit of normal) were reported in 29% of the US study patients (majority receiving folic acid) and 62% of the multinational study patients (majority not receiving folic acid). CONCLUSION: After using propensity scores to adjust for differences in the baseline characteristics of folic acid users and non-folic acid users, 9-21% fewer MTX-treated RA patients taking folic acid had ACR 20%, 50%, or 70% improvement at 52 weeks compared with those who did not receive folic acid in the 2 phase III RA clinical trials. As a post hoc analysis, the results of this data analysis should be considered "hypothesis generating" and an impetus for future studies regarding the effects of folic acid on the efficacy of MTX in RA.     

Homocysteine and folate status in methotrexate-treated patients with rheumatoid arthritis

OBJECTIVE: To study (i) the influence of methotrexate (MTX) therapy on homocysteine and folate metabolism in patients with rheumatoid arthritis (RA), (ii) the influence of the C677T mutation in the methylenetetrahydrofolate reductase gene (MTHFR) on the change in plasma homocysteine levels during MTX treatment, and (iii) the interference of folate and homocysteine metabolism with the efficacy and toxicity of treatment with MTX. METHODS: The 113 patients enrolled in this study were participating in a 48-week, multicentre, double-blind, placebo-controlled study comparing the efficacy and toxicity of MTX treatment with and without folic or folinic acid supplementation. The MTX dose was 7.5 mg/week initially and increased to a maximum of 25 mg/week if necessary. Concentrations of total folate, 5-methyl tetrahydrofolate (in serum and in erythrocytes) and of homocysteine, cysteine and cysteine-glycine and the MTHFR genotype were determined before the start of the study, after 6 weeks, and after 48 weeks or on withdrawal from the study. Blood was drawn from fasting patients at a standardized time in the morning, 16 h after intake of MTX. The laboratory results were related to parameters of efficacy and toxicity of MTX treatment. RESULTS: Baseline values were distributed equally in the three treatment groups. The mean plasma homocysteine level (normal range 6-15 micromol/l) before the start of MTX was relatively high in all groups: 15.4 micromol/l [95% confidence interval (CI) 13.5 to 17.2] in the MTX plus placebo group (n=39), 14.3 micromol/l (95% CI 12.2 to 16.4) in the MTX plus folic acid group (n=35) and 15.9 micromol/l (95% CI 13.7 to 18.1) in the MTX plus folinic acid group (n=39). After 48 weeks of MTX therapy, the mean homocysteine level showed an increase in the placebo group (+3.6 micromol/l, 95% CI 1.7 to 5.6). In contrast, a decrease was observed in the groups supplemented with folic or folinic acid (folic acid, -2.7 micromol/l, 95% CI -1.4 to -4.0; folinic acid, -1.6 micromol/l, 95% CI -0.1 to -3.0). The differences in the change in plasma homocysteine level between the placebo group and each of the two folate-supplemented groups were statistically significant (P<0.0001), contrary to the difference between the folic and folinic acid groups (P=0.26). Linear regression analysis showed that the change in plasma homocysteine level was statistically significantly associated with folic or folinic acid supplementation (P=0.0001) but not with the presence or absence of the C677T mutation in the MTHFR gene. Homozygous mutants had a higher plasma homocysteine concentration at baseline. No relationship was found between the change in disease activity and the change in homocysteine concentration or the mean homocysteine concentration after 48 weeks of MTX therapy. Toxicity-related discontinuation of MTX treatment was not associated with the change in homocysteine concentration. CONCLUSIONS: Low-dose MTX treatment in RA patients leads to an increased plasma homocysteine level. Concomitant folate supplementation with either folic or folinic acid decreases the plasma homocysteine level and consequently protects against potential cardiovascular risks. No relationship was found between the change in homocysteine concentration and the presence or absence of the C677T mutation in the MTHFR gene. Homocysteine metabolism was not associated with efficacy or toxicity of MTX treatment.     

Effect of folic or folinic acid supplementation on the toxicity and efficacy of methotrexate in rheumatoid arthritis: a forty-eight week, multicenter, randomized, double-blind, placebo-controlled study

OBJECTIVE: To study the effect of folates on discontinuation of methotrexate (MTX) as single-drug antirheumatic treatment due to toxicity, to determine which type of adverse events are reduced, to study the effects on the efficacy of MTX, and to compare folic with folinic acid supplementation in a 48-week, randomized, double-blind, placebo-controlled trial. METHODS: Patients with active RA (n = 434) were randomly assigned to receive MTX plus either placebo, folic acid (1 mg/day), or folinic acid (2.5 mg/week). The initial MTX dosage was 7.5 mg/week; dosage increases were allowed up to a maximum of 25 mg/week for insufficient responses. Folate dosages were doubled once the dosage of MTX reached 15 mg/week. The primary end point was MTX withdrawal because of adverse events. Secondary end points were the MTX dosage and parameters of efficacy and toxicity of MTX. RESULTS: Toxicity-related discontinuation of MTX occurred in 38% of the placebo group, 17% of the folic acid group, and 12% of the folinic acid group. These between-group differences were explained by a decreased incidence of elevated liver enzyme levels in the folate supplementation groups. No between-group differences were found in the frequency of other adverse events or in the duration of adverse events. Parameters of disease activity improved equally in all groups. Mean dosages of MTX at the end of the study were lower in the placebo group (14.5 mg/week) than in the folic and folinic acid groups (18.0 and 16.4 mg/week, respectively). CONCLUSION: Both folate supplementation regimens reduced the incidence of elevated liver enzyme levels during MTX therapy, and as a consequence, MTX was discontinued less frequently in these patients. Folates seem to have no effect on the incidence, severity, and duration of other adverse events, including gastrointestinal and mucosal side effects. Slightly higher dosages of MTX were prescribed to obtain similar improvement in disease activity in the folate supplementation groups.     

Folic acid supplementation during methotrexate immunosuppression is not associated with early toxicity, risk of acute graft-versus-host disease or relapse following hematopoietic transplantation

Methotrexate (MTX) is used as an immunosuppressive agent for acute graft-versus-host disease (GVHD) prophylaxis following hematopoietic cell transplantation (HCT). Concerns that folate intake may impair MTX effectiveness or selectively rescue leukemic cells have led to variations in clinical practice regarding supplemental folic acid during MTX administration. A retrospective, observational study was undertaken to determine the association between folic acid intake (days 0-18 post transplant) and MTX toxicity and efficacy following HCT. The study population consisted of 311 adult patients who received a myeloablative HCT for chronic myelogenous leukemia, all four scheduled doses of MTX, and did not require leucovorin rescue. Multiple linear regression models were used to assess the relationships between folic acid intake (days 0-18 post-HCT) and oral mucositis index (OMI) scores, time to engraftment and risk of detectable acute GVHD. No statistically significant differences in mean OMI scores, time to engraftment, risk of acute GVHD, days to acute GVHD, risk of relapse or survival were observed when comparing patients taking, on average, <400 (14%), 400 (58%) or >400 microg (28%) folic acid per day. Our results suggest that concurrent folic acid supplementation does not change MTX effectiveness or toxicity in this patient population.     

Folate supplementation and methotrexate treatment in rheumatoid arthritis: a review

OBJECTIVES: The folate antagonist methotrexate (MTX) has become established as the most commonly used disease-modifying anti-rheumatic drug (DMARD) in the treatment of rheumatoid arthritis (RA) but is commonly discontinued due to adverse effects. Adverse effects are thought to be mediated via folate antagonism. In this paper we summarize the current data on the use of folates as a supplement to MTX use in RA for the prevention of adverse effects and as a potential modulator of cardiovascular risk, and propose guidelines for standard practice. METHODS: A Medline search was performed using the search terms "methotrexate", "folic acid", "folinic acid", "folate" and "homocysteine". Literature relevant to the use of folates as a supplement to MTX in the treatment of RA was reviewed and other papers referred to as references were explored. RESULTS: The use of supplemental folates, including folic and folinic acid, in RA patients treated with MTX has been shown to improve continuation rates by reducing the incidence of liver function test abnormalities and gastrointestinal intolerance. Folate supplements do not appear to significantly reduce the effectiveness of MTX in the treatment of RA. Furthermore, supplemental folic acid offsets the elevation in plasma homocysteine associated with the use of MTX. This may in turn reduce the risk of cardiovascular disease, which is over-represented amongst patients with RA, and for which hyperhomocysteinaemia is now recognized as an independent risk factor. CONCLUSIONS: We propose that folic acid supplements be prescribed routinely to all patients receiving MTX for the treatment of RA. We recommend a pragmatic dosing schedule of 5 mg of oral folic acid given on the morning following the day of MTX administration.     

Folic acid alters methotrexate availability in patients with rheumatoid arthritis

OBJECTIVE: To evaluate the effects of repeated doses of folic acid on the pharmacokinetics of methotrexate (MTX) in patients with rheumatoid arthritis. METHODS: We studied 20 patients (ages 30-78 years) who received MTX intramuscularly (10 mm/week). MTX was administered alone or after treatment with folic acid (5 mg tablet once daily) for 13 days. Plasma samples were collected 2 and 8 h after dose intake. MTX concentrations in plasma and ultrafiltrate samples were measured by fluorescence polarization immunoassay. A Bayesian approach was used to determine individual MTX pharmacokinetic variables to minimize the number of samples collected. RESULTS: Folic acid supplementation led to reduced plasma MTX levels 2 and 8 h after MTX administration and reduced area under the plasma MTX concentration versus time curve (AUC) (about 20%; p < 0.02). Total clearance of MTX and Vd were higher when patients were also receiving folic acid than when they were taking MTX alone (p < 0.02). The plasma protein binding of MTX remains unchanged. CONCLUSION: The lower plasma MTX concentrations in patients taking folic acid supplements could be interpreted as increased cellular uptake of MTX; the folic acid supplements would promote the sequestering of MTX intracellularly. The decrease of MTX concentrations leads to reduced AUC; it is also possible that there are reduced AUC combined with increased intracellular folate levels. These results reopen the question of whether folic acid should be used immediately in all patients when MTX is begun.     

The effect of folic acid and folinic acid supplements on purine metabolism in methotrexate‐treated rheumatoid arthritis

Objective

To determine if folinic acid supplementation during methotrexate (MTX) therapy for rheumatoid arthritis (RA) reduces both urinary 5‐aminoimidazole‐4‐carboxamide (AICA) and urinary adenosine excretion more than does folic acid supplementation. AICA and adenosine are markers for MTX interference with purine metabolism.

Methods

Forty patients with RA who received MTX for 6 weeks were randomized to receive either daily folic acid or folinic acid supplements during an additional week of MTX therapy. Colorimetric and radioimmunocompetition assays were used to measure 24‐hour urinary AICA and adenosine excretion levels, respectively.

Results

At the end of 6 weeks, 24‐hour urinary levels of AICA, but not adenosine, were elevated as compared with baseline levels (i.e., prior to MTX therapy). Folinic acid, but not folic acid, supplementation normalized urinary AICA levels during MTX therapy. Relatively high urinary levels of AICA were correlated with reduced disease activity. No similar correlations were seen with urinary adenosine levels.

Conclusion

The blockade of purine nucleotide biosynthesis by MTX at the AICA ribonucleotide transformylase–catalyzed step may be related to the efficacy of MTX, and this blockade is effectively relieved by folinic acid, but not by folic acid, supplementation.

     

甲氨蝶呤在国人类风湿关节炎治疗中不良反应的调查及分析

目的 调查类风湿关节炎(RA)患者治疗中服用甲氨蝶呤(MTX)及其不良反应发生情况.方法 以现场问卷调查的形式记录325例RA患者服用MTX及其相关不良反应.采用SPSS 11.5软件进行统计分析.率的比较采用x2检验.结果 ①服用MTX患者总不良反应发生11例,占34.2%,其中胃肠道反应发生率最高(64例,占19.7%).总停药43例,占13.2%,其中肝功能损害停药率最高(17例,占5.2%).胃肠道反应及口腔溃疡发生时间在1周之内,肝功能受损、白细胞减少一般1～2个月.②MTX不良反应的发生率随服用剂量的增加而升高.③服用叶酸组不良反应发生率均低于未服叶酸组.结论 MTX治疗RA不良反应较常见,程度较轻,但应定期随访,避免严重不良反应的发生.补充叶酸可明显增加患者的耐受性.     

The C677T mutation in the methylenetetrahydrofolate reductase gene: a genetic risk factor for methotrexate-related elevation of liver enzymes in rheumatoid arthritis patients.

OBJECTIVE: To study the possible relationship between the C677T mutation in the methylenetetrahydrofolate reductase (MTHFR) gene and the toxicity and efficacy of treatment with methotrexate (MTX) in patients with rheumatoid arthritis (RA). METHODS: Genotype analysis of the MTHFR gene was done in 236 patients who started MTX treatment with (n = 157) or without (n = 79) folic or folinic acid supplementation. Outcomes were parameters of efficacy of MTX treatment, patient withdrawal due to adverse events, discontinuation of MTX treatment because of elevated liver enzyme levels, and the total occurrence of elevated liver enzyme levels during the study. Multivariate logistic regression analysis was used to study the relationship between the presence of the MTHFR C677T mutation and toxicity outcomes of MTX treatment. RESULTS: Forty-eight percent of the patients showed the homozygous (T/T) or heterozygous (T/C) mutation. The presence of the C677CT or C677TT genotypes was associated with an increased risk of discontinuing MTX treatment because of adverse events (relative risk 2.01; 95% confidence interval 1.09, 3.70), mainly due to an increased risk of elevated liver enzyme levels (relative risk 2.38; 95% confidence interval 1.06, 5.34). Efficacy parameters were not significantly different between the patients with and those without the mutation. CONCLUSION: The C677T mutation is the first identified genetic risk factor for elevated alanine aminotransferase values during MTX treatment in patients with RA. We postulate that the incidence of clinically important elevation of liver enzyme levels during MTX treatment is mediated by homocysteine metabolism. Supplementation with folic or folinic acid reduced the risk of toxicity-related discontinuation of MTX treatment both in patients with and in patients without the mutation.     

A clinical study of CPH 82 vs methotrexate in early rheumatoid arthritis

OBJECTIVES: The objectives of this study were to evaluate the therapeutic efficacy of CPH 82 in comparison with methotrexate (MTX) in adult patients with early, active rheumatoid arthritis (RA) and to compare the tolerance and safety profiles of the two drugs. METHODS: The study was a 24-week, double-blind, randomized study in 10 centres of 100 patients with active RA, with a disease duration of less than 2 yr at the start of treatment, which consisted of either CPH 82 300 mg/day or MTX 10 mg/week. The six primary effect variables were: number of swollen joints, Ritchie's articular index, patient's pain score, patient's global score, Health Assessment Questionnaire (HAQ) and C-reactive protein (CRP). Erythrocyte sedimentation rate (ESR), physician's global score and the efficacy according to the European League Against Rheumatism (EULAR) and American College of Rheumatology (ACR) response criteria were also analysed. RESULTS: There was a significant improvement for both drugs in all variables. Significant differences between the drugs in favour of MTX were found only in patient's pain score, CRP and ESR. By the EULAR criteria, 76% and 86% were judged to be responders in the CPH 82 and MTX groups, respectively. By the ACR criteria, the corresponding figures were 58% and 64%. The most common side-effects were gastrointestinal, which were similar in both groups. The numbers of treatment failures due to adverse events were two with CPH 82 and 14 with MTX. CONCLUSIONS: The clinical effect of CPH 82 in this study was comparable to that of MTX at a dose of 10 mg/week. Both drugs reduced acute-phase reactants, MTX more effectively than CPH 82. The safety profile of CPH 82 was more favourable than that of MTX without folic acid supplementation.     

Durability of treatment with methotrexate in Venezuelan patients with rheumatoid arthritis

A multicenter, national, retrospective, and cross-sectional study of 219 hospital-based Venezuelan patients with rheumatoid arthritis (RA) was aimed to evaluate the probability of continuity of treatment with oral methotrexate (MTX). Treatment survival decreased from 92% at 12 months to 42% at 180 months, as assessed by life table analysis and the Kaplan–Meier method. Forty-seven patients stopped treatment and adverse effects (29.7%) and lack of continuous access to medication (19.1%) were the most common causes for withdrawal. MTX survival was decreased in the group with combined MTX plus leflunomide therapy, as shown by the log-rank test. Venezuelan patients with RA have a probability of continuing treatment with oral MTX comparable to non-Hispanic patient populations. However, concomitant use of leflunomide may increase the risk of interruption of MTX treatment in this RA population.     

Comparison of two schedules for administering oral low-dose methotrexate (weekly versus every-other-week) in patients with rheumatoid arthritis in remission: a twenty-four week, single blind, randomized study.

OBJECTIVE: To compare the efficacy of 2 low-dose oral methotrexate (MTX) schedules in maintaining remission in patients with rheumatoid arthritis (RA). METHODS: Patients with RA were included if they were receiving treatment with weekly MTX for at least 9 months and the RA was in remission (defined by American College of Rheumatology [ACR] criteria) for at least 6 months. Patients were stratified by treatment and randomly assigned to weekly or every-other-weekly (EOW; reducing their monthly dose by half) treatment with MTX. Patients were evaluated by a rheumatologist (blinded to the treatment schedule) at baseline and at 6, 12, and 24 weeks. The evaluations included joint counts, Ritchie Articular Index, Health Assessment Questionnaire Disability Index, physician's and patient's global health assessments, visual analog scale for pain, and incidence of adverse effects. Laboratory evaluations were done at baseline and at week 24. RESULTS: Fifty-one patients were included (26 taking weekly MTX, 25 taking EOW MTX). Baseline comparisons showed no differences between the groups. The mean duration of RA was <3 years in both groups, and they had been started on weekly MTX treatment early after diagnosis. After 24 weeks, >90% of the patients in both groups continued in remission. Evaluations of disease activity at 6 and 12 weeks showed no between-group differences. EOW MTX patients who experienced relapse were switched back to weekly MTX, and after a few weeks, their RA was again controlled. The incidence of adverse effects was slightly higher in the weekly MTX group, although the difference did not reach statistical significance. The observed laboratory values were very similar for both groups, except for the serum aspartate aminotransferase and alanine aminotransferase levels, which decreased in the EOW MTX group and were statistically significant at week 24 (P = 0.04 and P = 0.006, respectively). CONCLUSION: EOW MTX represents a valid therapeutic alternative for a specific subgroup of RA patients, as outlined by the ACR remission criteria. Patients with a short disease duration who were treated early after disease onset with weekly MTX and who achieve sustained remission have a higher probability of success with the EOW MTX schedule.     

Effect of folic or folinic acid supplementation on the toxicity and efficacy of methotrexate in rheumatoid arthritis: A forty‐eight–week,multicenter, randomized,double‐blind,placebo‐controlled study

Objective

To study the effect of folates on discontinuation of methotrexate (MTX) as single‐drug antirheumatic treatment due to toxicity, to determine which type of adverse events are reduced, to study the effects on the efficacy of MTX, and to compare folic with folinic acid supplementation in a 48‐week, randomized, double‐blind, placebo‐controlled trial.

Methods

Patients with active RA (n = 434) were randomly assigned to receive MTX plus either placebo, folic acid (1 mg/day), or folinic acid (2.5 mg/week). The initial MTX dosage was 7.5 mg/week; dosage increases were allowed up to a maximum of 25 mg/week for insufficient responses. Folate dosages were doubled once the dosage of MTX reached 15 mg/week. The primary end point was MTX withdrawal because of adverse events. Secondary end points were the MTX dosage and parameters of efficacy and toxicity of MTX.

Results

Toxicity‐related discontinuation of MTX occurred in 38% of the placebo group, 17% of the folic acid group, and 12% of the folinic acid group. These between‐group differences were explained by a decreased incidence of elevated liver enzyme levels in the folate supplementation groups. No between‐group differences were found in the frequency of other adverse events or in the duration of adverse events. Parameters of disease activity improved equally in all groups. Mean dosages of MTX at the end of the study were lower in the placebo group (14.5 mg/week) than in the folic and folinic acid groups (18.0 and 16.4 mg/week, respectively).

Conclusion

Both folate supplementation regimens reduced the incidence of elevated liver enzyme levels during MTX therapy, and as a consequence, MTX was discontinued less frequently in these patients. Folates seem to have no effect on the incidence, severity, and duration of other adverse events, including gastrointestinal and mucosal side effects. Slightly higher dosages of MTX were prescribed to obtain similar improvement in disease activity in the folate supplementation groups.